docs: def parse_route(cls, template):
          """ Parse a route definition, and return the compiled regex that matches it.
          """
          regex = ''
          last_pos = 0
  
          for match in cls.ROUTES_RE.finditer(template):
              regex += re.escape(template[last_pos:match.start()])
              var_name = match.group(1)
              expr = match.group(2) or '[^/]+'
              expr = '(?P<%s>%s)' % (var_name, expr)
              regex += expr
              last_pos = match.end()
  
          regex += re.escape(template[last_pos:])
          regex = '^%s$' % regex
  
          return re.compile(regex)